243 OCW test using H4350 Need opinions

I chronoed some other rounds just before to make sure it was working properly and they were fine. I'm gonna back it off a bit to see if I can get the ejector marks to go away. I should be able to get 3k out of it anyway.

My rifle has a 1/8 brougthon barrel .243, 24". Chamber was cut with a custom reamer tight necked at .269 from PTG, specifically made for 107 SMK or 105 VLD.

Dont go for speed. H4831 is a slower burning powder, 4350 is hotter. Im very sure you can stabalize your load. start low on powder charge and increase little at a time. I started at 40.0 with 4831 and my groups was open. as I started to increase powder charge they got way lot better as speed was increased. I settled for 40.5 of h4831sc for the 105 vld and 40.6 H4831sc for 107 SMK. I hope it helps

If you are looking for the OCW load you should be looking at the 40.5-41gr. load. The 40gr load shifts the point of impact and the 40, 40.5, 41.0 and 41.5 are all within 1moa. I would try 40.7 and seat the bullets +.005 and -.005 and see what those do. The whole concept of an OCW load is to be in the middle of a point of impact node so to speak. I would also shoot them at at least 200 if not 300yds. as well.

I think you are way up there in pressure to get those velocities. Your chronied loads show it too. Notice the 70fps increase, then only 20. I'm sorry, but I think you are missing the boat here on what a true OCW load is. Your loads are also 2 grouping which is a bullet seating issue in my experience. If you must, shoot the 40.7 load while adjusting seating depth, but I still think even that's too hot. Go to 200yds too. The holes in your 100yd. targets don't look at all keyholed to me. I recommend going back to around 39 and adjust your seating depth.

I wen back to the range. I started at 37.3 and worked my way up to 40. Found some good results from the round robin shooting. Now I am gonna chrono the loads that looked best and look at seating depth to gain the accuracy I want. Thanks for all the input